How to know that a triangle triple exists in our array?

Question

I was stuck in solving the following interview practice question:
I have to write a function:

int triangle(int[] A);

that given a zero-

Answer 1

public static int solution(int[] A) {
    // write your code in Java SE 8
    long p, q, r;
    int isTriangle = 0;

    Arrays.sort(A);
    for (int i = 0; i < A.length; i += 1) {

        if (i + 2 < A.length) {
            p = A[i];
            q = A[i + 1];
            r = A[i + 2];
            if (p >= 0) {
                if (Math.abs(p) + Math.abs(q) > Math.abs(r) && Math.abs(q) + Math.abs(r) > Math.abs(p) && Math.abs(r) + Math.abs(p) > Math.abs(q))
                    return 1;
            }
        } else return 0;


    }

    return isTriangle;

}

The above implementation is Linear in time complexity. The concept is simple use the formaula they gave extracting a series of triplets of sorted elements.